A Review On Carbon Nanotubes Production Via Catalytic Methane Decomposition.

Methane decomposition is a promising approach to produce high purity, high yield and perfect orientation of carbon nanotubes and is viable for scaling up its production at a relatively low cost

Psychometric assessment of the short-form Child Perceptions Questionnaire: an international collaborative study.

OBJECTIVE: To examine the factor structure and other psychometric characteristics of the most commonly used child oral-health-related quality-of-life (OHRQoL) measure (the 16-item short-form CPQ11-14 ) in a large number of children (N = 5804) from different settings and who had a range of caries experience and associated impacts. METHODS: Secondary data analyses used subnational epidemiological samples of 11- to 14-year-olds in Australia (N = 372), New Zealand (three samples: 352, 202, 429), Brunei (423), Cambodia (244), Hong Kong (542), Malaysia (439), Thailand (220, 325), England (88, 374), Germany (1055), Mexico (335) and Brazil (404). Confirmatory factor analysis (CFA) was used to examine the factor structure of the CPQ11-14 across the combined sample and within four regions (Australia/NZ, Asia, UK/Europe and Latin America). Item impact and internal reliability analysis were also conducted. RESULTS: Caries experience varied, with mean DMFT scores ranging from 0.5 in the Malaysian sample to 3.4 in one New Zealand sample. Even more variation was noted in the proportion reporting only fair or poor oral health; this was highest in the Cambodian and Mexican samples and lowest in the German sample and one New Zealand sample. One in 10 reported that their oral health had a marked impact on their life overall. The CFA across all samples revealed two factors with eigenvalues greater than 1. The first involved all items in the oral symptoms and functional limitations subscales; the second involved all emotional well-being and social well-being items. The first was designated the 'symptoms/function' subscale, and the second was designated the 'well-being' subscale. Cronbach's alpha scores were 0.72 and 0.84, respectively. The symptoms/function subscale contained more of the items with greater impact, with the item 'Food stuck in between your teeth' having greatest impact; in the well-being subscale, the 'Felt shy or embarrassed' item had the greatest impact. Repeating the analyses by world region gave similar findings. CONCLUSION: The CPQ11-14 performed well cross-sectionally in the largest analysis of the scale in the literature to date, with robust and mostly consistent psychometric characteristics, albeit with two underlying factors (rather than the originally hypothesized four-factor structure). It appears to be a sound, robust measure which should be useful for research, practice and policy

Review Of Carbon Nanotubes Growth And Synthesis.

Carbon nanotubes are tubular nanostructures derived from rolled graphene planes. Carbon nanotubes are fullerenes related structures but a fullerenes's carbon form a sphere; while a nanotubes are cylindrical. The growth mechanism of carbon nanotubes depend on the synthesis method

A Life Threatening Stridor Due to Huge Retrosternal Goitre: A Case Report

A retrosternal goiter, also known as a substernal gaiter, is an enlarged thyroid gland that grows downwards and extends through the thoracic inlet into the thoracic cavity. We present a case of retrosternal goiter that presented with recurrent attacks of breathlessness and was misdiagnosed as bronchial asthma for years and treated with steroids and bronchodilators. The patient presented with inspiratory stridor and the diagnosis was confirmed by a CT scan of the neck and chest. Total thyroidectomy was performed through a cervical approach and the stridor disappeared completely after surgery

Investigating the repair of cracks through bacterial self-healing for sustainable concrete in aggressive sulfate attack environments

Concrete completely submerged in sulfate solutions has been used as the primary study subject for the durability of concrete subjected to sulfates. On the other hand, empirical data from the field indicates that concrete exposed to sulfates may exhibit physical attack-induced surface scaling above. This study aims to study the two different types of local bacteria, (BS) and (BM), with content of 0%, 0.25%, 1%, 2.50%, and 5.00% by cement weight used in this work under curing in sulfate to examine the efficiency of bacterial self-healing of cracks for sustainable concrete in aggressive sulfate attack environments. The results show that in both curing in freshwater, FW, and sulfate, SUL, the optimum bacteria ratio was 2.5% BM, and the compressive strength improved by 43.34% for FW and 47.65% for sulfate. On the other hand, the results proved that the crack-filling and crack-repairing methods may be considered quicker than conventional methods. Moreover, a detailed conclusion about the preparation and processing of bacteria to provide the most significant content of locally accessible bacteria in Egypt, mainly when using chemical and mineral additives

Mesoporous Inorganic Membrane Reactor for Oxidative Coupling of Methane

The mesoporous inorganic membrane has been developed and characterized for oxidative coupling of methane reactions. In this research, g-alumina membrane was modified with Lanthanum. The membrane has shown thermal stability in prolonged exposure to the high-temperature application of 600-900°C. The results were confirmed by TGA and OCM experimentations. TGA results showed only 2-3% loss from an initial weight that is mainly due to evaporation of water and release of the nitrate compound. The membrane was also found stable for at least a month of operation while the catalyst was being regenerated to regain its activity. The SEM cross-sections show successful deposition of Lanthanum in spite of its non-uniform deposition layer and crack formation

Visitors’ preferences on seasonal accommodation for the Rainforest World Music Festival / A.R. Mohd Ariffin and Mohd Khairil Naim Mohamed Jamel

Sarawak Cultural Village (SCV) is an award-winning open-air living museum of Sarawak has been the host to the three days annual Rainforest World Music Festival (RWMF) since 2005. Every year, thousands of visitor flock to SCV grounds to experience the rich Sarawak culture, live performances and celebrations that it offers. Due to its popularity, each year the number of visitors increases with regulars and newcomers. This has created a spike in accommodation demands for the area of Santubong. Unfortunately, the growth of visitors is not supported by adequate desired accommodations within the area. Thus, the objectives of this paper are to identify an ideal seasonal accommodation type and desired basic facilities required during RWMF. Quantitative analysis is incorporated in this research through collection of data gathered from online survey. Set of questionnaires was distributed to the former visitors seeking their views on the seasonal accommodations and facilities preferred. Based on the results of the data collected, it provided some understanding on the seasonal accommodations and facilities that are suitable for RWMF. This finding consequently could help provide a feasible and practical solution towards the spike demand for accommodation facilities during the RWMF